Drawing barbs

A barb is a representation of the speed and direction of wind, and is mainly deployed by meteorology scientists. In theory, they can be used to visualize any type of two-dimensional vector quantities. They are similar to arrows (quivers), but the difference is that arrows represent vector magnitude by the length of the arrow, while barbs give more information about the vector's magnitude by employing lines or triangles as increments of magnitude.

We will explain what barbs are, how to read them, and how to visualize them using Python and matplotlib. Here's a typical set of barbs:

In the preceding diagram, the triangle, also known as flag, represents the largest increment.

A full line or barb represents a smaller increment; a half line is the smallest increment.

The increments are in the order of 5, 10, and 65 for a half-line, line, and triangle, respectively. The values here represent, for meteorologists at least, wind speed in nautical miles per hour (knots).

We ordered the barbs...